Question: Simplify the following expression: $z = \dfrac{-5a}{2} - \dfrac{7a}{2}$
Solution: Since the expressions have the same denominator we simply combine the numerators: $z = \dfrac{-5a - (7a)}{2}$ Combine like terms: $z = \dfrac{-12a}{2}$ Simplify by dividing numerator and denominator by 2: $z = \dfrac{-6a}{1}$ $z = -6a$